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[CVO103]

How much can i mill the heads?
How much will the compression increase?
Is there any piston for this head?

Regards

J-O

[Talon]

It depends on a lot of thing, are you changing pistons, cam's, and what head gasket your going to use?

[DCFIREMANN]

OK J-O That was the pic I was looking for. Those are CVO heads.

You can mill up to 90 thou off the heads. I would not reccomend going that far. 30 thou will jump the compression up to about 10.5 to 1 if you have the SE after market pistions. You may want to use a 030 cometic head gasket as well. That will depend on what cams you are using. You don't want to much cranking pressure

Be Safe

THE DAWG

[CVO103]

I have the kit 29877-06 with pistons, cylinders and flywheel it's complete kit.
Wich aftermarket pistons?
I think it will be Andrews TW54 cams.

[johnsachs]

You can mill the heads to death,buttttttttttttt the major factor,in your case, is getting the 1 piece throttle body to fit.
As you mill,the distance between the cylinders decreases.
Be careful.
John

[Classic Beast]

Here is a chart that gives you an Idea of the compression ratio change when milling your heads, with a larger bore it has more effect.

Head Compression Ratio
Milling (T)               EV80                       Twin 88
.000 . . . . . . . . . . . 8.50 . . . . . . . . . . . . 9.00
.020 . . . . . . . . . . . 8.77 . . . . . . . . . . . . 9.33
.040 . . . . . . . . . . . 9.07 . . . . . . . . . . . . 9.69
.060 . . . . . . . . . . . 9.39 . . . . . . . . . . . . 10.09
.080 . . . . . . . . . . . 9.73 . . . . . . . . . . . . 10.52
.100 . . . . . . . . . . . 10.11 . . . . . . . . . . . 11.00

[Classic Beast]

On the pic of your heads it doesn't look like there is much of a quench area, just the chamfer around the bottom edge. If this chamfer matches the pistons then you will have to make sure it goes back in after milling or the pistons will hit. Also make sure you have at least .030" to allow for thermal growth. I have milled .050" on heads before and did notice the difference, beyond that and you might start running into clearance problems with the manifold, valves etc. The best way to increase compression though is with new pistons that are designed properly, 10.5 would probably be max for these heads and should be matched with the right cams to take advantage of them as if you don't increase the duration of the cam you could run into detonation problems as the stock cam timing is more suited to a lower compression.

[DCFIREMANN]

The 103 CVO motors come from the factory with a compression ratio of approx 8.7 to 1. If you do mill the heads on a daily street driver stay at about 20 to 30 thou. If you are looking to up the performance, you need to purchase a set of CVO aftermarket cams. Zippers Performance or Freedom Cycle make them. They have early closing events on the valve timing and raise the compression that way. They work very well. A lot of the members on this board have used them with much success.  While the heads are off you might as well clean up the ports and do a performance valve job as well as change the valve springs. Add a fueling pump and a Baisley spring with a good set of lifters and adjustable push rods and you will be good to go!!!!

Be Safe

THE DAWG 

[Classic Beast]

It looks like your kit is already at 9:1 with the matching but cast pistons. You could go with the 22483-04 Pistons to give you 10.5 / 1 these will be matched to your heads. I would go with the 258 cams Put in the Zippers thunder max ECM with the Oxygen sensors and the larger Zippers 54mm throttle body and you should be good to go. If you have the cash have your heads cleaned up match the ports and cc the combustion chambers this is free HP as long as you don't go too extreme.

29877-06
SCREAMIN’ EAGLE® STREET LEGAL
103 CUBIC INCH STAGE I KIT FOR EFI MODELS
Bring your ’03-’06 Twin Cam motorcycle up to a whopping
1690cc. This 50-state street legal kit combines all the
proven components of the Screamin’ Eagle 103 cubic inch
models – the 4-3/8" stroker flywheel assembly, 3-7/8" big
bore cast pistons, big bore cylinders, SE-253 camshafts,
cylinder heads, air cleaner assembly and cover insert and
catalyst mufflers when required. The highlighted Screamin’
Eagle 103 cylinder heads and cast piston combination
offers a 9:1 compression ratio for easy starting. The cylinder
heads also prominently feature the “Screamin’ Eagle
103” script. Kit includes all required gaskets

[DCFIREMANN]

Classic Beast that would be a good build but he is in Sweedeen. If he hhas any problems tuning the Thunder max he will be S%&T out of luck. I know he can download a map that will be close but that is beyond some people. Unless he wants to change the pistons he would be better off with Zippers Red Shift TC575 cams.


Be Safe

THE DAWG

[Classic Beast]

Just finished a build in june with this exact set up in a 2005 RK and does it run sweet, gives my 127 a run for its money. Since he's in Sweden even more reason to stay with All harley parts (258 cams). I found with the Zippers just an email to them with the details and they sent us a map that worked perfect first time.  So the red shift 575's work good with 9/1, 103 I haven't tried them? I will have to remember that for next time. Thanks for the feedback. 

[DCFIREMANN]

Just finished a build in june with this exact set up in a 2005 RK and does it run sweet, gives my 127 a run for its money. Since he's in Sweden even more reason to stay with All harley parts (258 cams). I found with the Zippers just an email to them with the details and they sent us a map that worked perfect first time.  So the red shift 575's work good with 9/1, 103 I haven't tried them? I will have to remember that for next time. Thanks for the feedback. 

Yes they wrok very well. Plus they have a map already set up for the build.

Be Safe

THE DAWG

[Fired00d]

Yes they wrok very well. Plus they have a map already set up for the build.

Be Safe

THE DAWG

Don't have the Thundermax, but do have the cams (575's) and they put a smile on my face every time I twist the throttle.

 
Ride Safe,
Fired00d
 

[CVO103]

You could go with the 22483-04 Pistons to give you 10.5. 

Can i use this piston with "Screamin' Eagle 103" heads?

If i can i don't have to mill the heads.

J-O

[Classic Beast]

If thats the kit you bought then you have the 103+ heads these pistons are designed for them but check with harley just to make sure. They look like the 103+ heads though.



SCREAMIN’ EAGLE PRO TWIN CAM STROKER
PISTONS FOR “103+” CYLINDER HEADS*
These 3-7/8" Big Bore forged pistons feature a dome
shape that is matched to the Screamin’ Eagle “103+”
Cylinder Heads to maximize horsepower output. When used
in combination with the Screamin’ Eagle 103+ Cylinder
heads, Screamin’ Eagle Stroker Flywheels or 2007 Twin
Cam models with stock 4-3/8" stroke flywheels, and Big
Bore Cylinders, the resulting compression ratio is 10.5:1.
Complete kit includes pistons, rings, wrist pins and clips.
All EFI models require ECM calibration* (priced separately).
For race application only.
103 C.I. Big Bore
Fits ’99-later Twin Cam models equipped with Screamin’
Eagle 103+ Cylinder Heads, Screamin’ Eagle Stroker
Flywheels or 2007 Twin Cam models with stock 4-3/8"
stroke flywheels, and Big Bore Cylinders.
22483-04 Standard Bore (pair). $279.95
22484-04 .005" o/s (pair). $279.95
22485-04 .010" o/s (pair). $279.95

[macman]

Why would you want to mill the heads for more compression? All this does is cause more set up time and custom parts or more machine work (piston to valve clearance, push rod lenght, intake fitting)

Just buy the pistons with the compression ratio you want.

Save your money and get some of this done to your heads.

[DCFIREMANN]

Changing the pistons is the right way. But I always mill 30 thou off my heads even when the pistons are changed. It is free HP, well almost free!!!!! 

Be Safe

THE DAWG

[Classic Beast]

I believe this is not a 103 CVO but the 103 kit installed after, according to the part numbers you quoted. Be careful if you do decide to mill them down as if there is not a chamfer on the bottom of the head to match the pop up on the piston it could hit, besides if these pistons give you a 10.5 / 1 ratio I wouldn't go over that on the street with a heavy bike and tall gears unless you have access to fuel that is higher than 94 octane.

[DCFIREMANN]

Classic I think we are still trying to figure out what he wants or is going to do. If he goes with a cam with a bunch of duration and overlap then he will need to bump up the compression. The pics of the heads he showed us were in fact CVO heads.

Be Safe

THE DAWG

[Classic Beast]

I have the kit 29877-06 with pistons, cylinders and flywheel it's complete kit.
Wich aftermarket pistons?
I think it will be Andrews TW54 cams.

This says a different story and if you look at the pics of the 103+ heads they look the same, anyways I'm outta here do what you like.

[grc]

I'm personally not a big fan of milling heads to increase compression, especially versus using pistons designed specifically for the purpose.  I think you will get more bang for your buck by just cleaning up the ports, doing a good 5 angle valve job, and equalizing combustion chamber volumes.  Anything beyond that I would look at an aftermarket piston, head, and cam combination.  The CVO 103 head needs way too much work to become a true performance head, but if you want to stay with it then contact some of the folks who weld up and remachine them.  One such person is Short Block Charlie, who just happens to be a member here.

Jerry

[DCFIREMANN]

This says a different story and if you look at the pics of the 103+ heads they look the same, anyways I'm outta here do what you like.

No need to leave.

The combustion chamber is the same for the 103+ and the CVO heads. The pistons are the same weather for a 103 or a 113( if you buy SE). I have always been a fan of milling 30 thou off the heads. You made a statement about checking clearances. I ALWAYS CHECK PISTON TO VALVE CLEARENCE. If you don't you are looking for trouble. I don't care what grind you put in the motor. If you go to a grind with a lot of duration and over lap you will lose some of your compression ratio. This will help in those situations.

Be Safe

THE DAWG

[SPIDERMAN]

Best street cams in my humble opinion are those with moderate duration, short overlap and reasonably high lift   Such as 240 duration, 28 degrees of overlap and .570 lift   Check out SE257 and SE258 for H-D cams and those with similar profiles in the aftermarket


B B

[DCFIREMANN]

Best street cams in my humble opinion are those with moderate duration, short overlap and reasonably high lift    Such as 240 duration, 28 degrees of overlap and .570 lift   Check out SE257 and SE258 for H-D cams and those with similar profiles in the aftermarket


B B

BB you are correct. In a heavy bike you need some good TQ numbers to get the ball rolling. More lift and a short valve opening event. Then you can go pull some stumps!!!!

Be Safe

THE DAWG

[SPIDERMAN]

BB you are correct. In a heavy bike you need some good TQ numbers to get the ball rolling. More lift and a short valve opening event. Then you can go pull some stumps!!!!

Be Safe

THE DAWG

DAWG,
           Wanna bet Harry doesn't agree ? 

B B

[DCFIREMANN]

DAWG,
           Wanna bet Harry doesn't agree ? 

B B

NOPE!!!!! Unless he read it some where!!!!!!

Be Safe

THE DAWG

[Classic Beast]

It looks like your kit is already at 9:1 with the matching but cast pistons. You could go with the 22483-04 Pistons to give you 10.5 / 1 these will be matched to your heads. I would go with the 258 cams Put in the Zippers thunder max ECM with the Oxygen sensors and the larger Zippers 54mm throttle body and you should be good to go. If you have the cash have your heads cleaned up match the ports and cc the combustion chambers this is free HP as long as you don't go too extreme.

29877-06 Pistons

The 258 cams work great with this combination on a heavy bike

[skyhook]

I also like long cams such as the 258...seems like most bagger riders want their power in the lower rpms and you won't get it with the 258...unless you use near 11 to 1 compression...I had 251 cams in a 103 road king and they were great...if you really want lowrange power I'd use someting with 38* to 42* intake close...unfortunately H-D doesn't have a cam in this range...hopefully they'll realize they're losing sales and come out with one

[SPIDERMAN]

I also like long cams such as the 258...seems like most bagger riders want their power in the lower rpms and you won't get it with the 258...unless you use near 11 to 1 compression...I had 251 cams in a 103 road king and they were great...if you really want lowrange power I'd use someting with 38* to 42* intake close...unfortunately H-D doesn't have a cam in this range...hopefully they'll realize they're losing sales and come out with one

I'm running an SE257 with 10.5/1 compression and getting great results

B B

[skyhook]

I'm running 257 cams in my 110 dyna...even in a light bike it helps to keep revs above 2700...long cams are great if you don't mind revving

[SPIDERMAN]

I'm running 257 cams in my 110 dyna...even in a light bike it helps to keep revs above 2700...long cams are great if you don't mind revving

ahhhhhhh, errrrrrrrr, ummmmmmmmm   2700 is revving ? 

I usually keep my tach in the 3500 - 4500 range


B B

[skyhook]

no I mean below 2700 is soft with that cam even at 10.7 compression

[CVO103]

I have decide to go whit SE-251 cams. I understand that the cam lift is ok.
Piston 22483-04 if it possible? Does this fit? I have read the post that Dawg have sent to this forum? ( maybe hi is older and learn (become wise) by experience)? i don't now.
Milling the heads 30 thoue? If i have to do it.
Milling the head 30 (thoue) and the piston 22483-04 compression must be to high? Over 11.0:1 i think?

30 (thoue) it is about 0.8 in millimeters?
Regards


Jan-Olof

[DCFIREMANN]

Yes those are the right pistons. If you are going to order them, order  +.005 and have the pistons fitted to the cylinders.

Be Safe

THE DAWG

[Classic Beast]

I have decide to go whit SE-251 cams. I understand that the cam lift is ok.
Piston 22483-04 if it possible? Does this fit? I have read the post that Dawg have sent to this forum? ( maybe hi is older and learn (become wise) by experience)? i don't now.
Milling the heads 30 thoue? If i have to do it.
Milling the head 30 (thoue) and the piston 22483-04 compression must be to high? Over 11.0:1 i think?

30 (thoue) it is about 0.8 in millimeters it is best for me

Regards

Personally I wouldn't mill the heads as over 10.5/1 compression your asking for trouble on the street besides with the quench area on these 103+ heads that are designed to match the pistons the milling will interfere with this. With the 257 or 258 cams it would be better since the cam timing will take advantage of the higher compression as they both have more duration and overlap than the 251 although the 251 has higher lift. The 251 would have better low to midrange power. 22484-04 .005" o/s (pair). is the part number for the oversize pistons.


Jan-Olof

[SPIDERMAN]

For what it's worth, every time I've had a set of heads milled, I've developed issues with the cylinder studs pulling out of the cases at some point down the line. I do not personally recommed this practice anymore to anyone concerned with the longevity of their motor.

just my $0.02

B B

[porthole]

Yes those are the right pistons. If you are going to order them, order  +.005 and have the pistons fitted to the cylinders.

just cleaning up the ports, doing a good 5 angle valve job, and equalizing combustion chamber volumes. 

In days gone by (automotive world) i have done a few valve jobs, all dealer work.

Typically they were 1 angle. If we were doing the work for a "special" reason then I would do a 3 angle, and 5 angle wasn't in the picture back then.

But seeing the way heads, pistons and valves looked after thousands of miles, I am curious as to the long term benefits of going through the trouble of a 5 angle or fitting the pistons exactly to the cylinders.

Does it really continue to be an effective 10-20-30,000 mile down the road?

[DCFIREMANN]

ABSOLUTLY!!!!!

Be Safe

THE DAWG

[Classic Beast]

There is nothing wrong with a 5 or even 7 angle valve job the problem comes into play in the pursuit of maximum Horsepower where the seat is too narrow or too far out to the edge of the valve instead of in the centre. In days gone by there was also a 1 degree interference angle that helped with sealing but with todays modern machining tolerances this ususally is not needed anymore. Properly done heads give "free" power, reduce detonation and increase efficiancy without any downside. The ccing of the combustion chambers can dramaticly affect smoothness since if not matched you can have a difference in the combustion ratio of each cylinder. A change in the design of the combustion chamber can also be an advantage since many modern heads primary design is to reduce emissions. If power and or efficiancy is the primary goal the cylinder head will have a different design. If you compare the EVO bathtub design to the open chamber twinkie design you will see a larger quench area on the bathtub which helps with combustion chamber turbulance and more even burning. Check out Branch Okeefe or some of the other shops doing the proper research on what makes heads work.

[CVO103]

Now i have finished my building of my 103" inch engine. I used 22483-04 piston, cometic 0.030 gasket, SE-251 cams, kit 29877-06 and new bearings.

The result is 101 horsepower and 150 Nm torque  (111 ft-lbs?)